This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Patients with end-stage renal disease (ESRD) suffer from very high rates of cardiovascular morbidity and morality, and high blood pressure and sympathetic hyperactivity certainly contibute to the increase in cardiovascular events. The first part of this study will examine whether or not muscle deconditioning and abnormal muscle reflexes activate the sypathetic nervous system in ESRD patients. The second part of the study will then examine whether or not intradialytic exercise ameliorates hypertension, sympatheic hyperactivity, and normalizes muscle reflex activation of the sympathetic nervous system. If exercise therapy is ofund to be beneficial, then intradialytic exercise may become a mainstream part of the therapeutic regimen to decrease cardiovascular risk in patients with ESRD.